package com.ruoyi.multab.websocket;

import org.springframework.stereotype.Component;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;

@ServerEndpoint("/webSocket/{sid}")
@Component
public class WebSocketServer {

	// 静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
	private static AtomicInteger onlineNum = new AtomicInteger();

	// concurrent包的线程安全Set，用来存放每个客户端对应的WebSocketServer对象。
	private static ConcurrentHashMap<String, Session> sessionPools = new ConcurrentHashMap<>();

	// 发送消息
	public void sendMessage(Session session, String message) throws IOException {
		if (session != null) {
			synchronized (session) {
//                System.out.println("发送数据：" + message);
				session.getBasicRemote().sendText(message);
			}
		}
	}

	// 给指定用户发送信息
	public void sendInfo(String userName, String message) {
		Session session = sessionPools.get(userName);
		try {
			sendMessage(session, message);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	// 建立连接成功调用
	@OnOpen
	public void onOpen(Session session, @PathParam(value = "sid") String userName) {
		sessionPools.put(userName, session);
		addOnlineCount();
		System.out.println(userName + "加入webSocket！当前人数为" + onlineNum);
//		try {
//			sendMessage(session, "欢迎" + userName + "加入连接！");
//		} catch (IOException e) {
//			e.printStackTrace();
//		}
	}

	// 关闭连接时调用
	@OnClose
	public void onClose(@PathParam(value = "sid") String userName) {
		sessionPools.remove(userName);
		subOnlineCount();
		System.out.println(userName + "断开webSocket连接！当前人数为" + onlineNum);
	}

	// 收到客户端信息
	@OnMessage
	public void onMessage(String message) throws IOException {
		message = "客户端：" + message + ",已收到";
		System.out.println(message);
		for (Session session : sessionPools.values()) {
			try {
				sendMessage(session, message);
			} catch (Exception e) {
				e.printStackTrace();
				continue;
			}
		}
	}

	// 错误时调用
	@OnError
	public void onError(Session session, Throwable throwable) {
		System.out.println("发生错误");
		throwable.printStackTrace();
	}

	public static void addOnlineCount() {
		onlineNum.incrementAndGet();
	}

	public static void subOnlineCount() {
		onlineNum.decrementAndGet();
	}
}